Yawning Might Be Doing More for Your Brain Than You Think

You Should Know: Yawning is one of those things your body does somewhat involuntarily, and scientists are still trying to work out exactly why. The old idea that yawning pulls in extra oxygen for your brain has largely been ruled out, although researchers now think it might help wake up your brain or regulate its temperature. Why yawning is contagious, however, remains poorly understood.

Going Deeper: A new study published in Respiratory Physiology & Neurobiology had 22 participants undergo MRI scans while yawning naturally or trying to suppress one. They found that yawning moved cerebrospinal fluid (the liquid that cushions your brain and spinal cord) away from the brain, pushing blood flow out to make room for fresh blood. Experts say this suggests yawning may support the glymphatic system, basically the waste clearance pathway for your brain. Some researchers describe it as a backup pump that kicks in when sleep isn’t doing enough to cover that.

Takeaway: The study doesn’t prove yawning is actively cleaning your brain, but it does suggest yawning is doing a lot more under the hood than we previously thought.

Bottom Line: Now you have a pretty good excuse for the next time you yawn in a meeting.